Report: Advertisers Could Track You Via a Smartphone's Accelerometer

Careful how you handle your phone: researchers have been testing out new surveillance techniques, and they think that you could easily be tracked around the web using your phone's accelerometer.

That might sound a little cooky, but according to the SFGate security researcher Hristo Bojinov has discovered that it's possible to distinguish between individual devices simply analyzing the data that accelerometers—devices which measure the physical motion of your phone—provide to webpages. Interestingly, that's a result of imperfections in the way that accelerometers actually work.

No accelerometer works perfectly, so they all provide (unique) outputs even when at rest. According to Bojinov that's enough to track a smartphone around the web. All a site need do is use a small piece of code that grabs your smartphone's accelerometer data. In fact, Bojinov has even implemented that on a Stanford website where you can view your own mobile's accelerometer footprint.

It's unclear whether or not this technique has been used by websites and advertisers, but Bojinov claims he'd be surprised if someone somewhere wasn't already exploring the possibility. Add to that that motion-detection is becoming ever more sensitive—think of the iPhone 5S's M7 chip, for instance—and the chances are that this could be an increasingly likely avenue of snooping. The research will be formally published in the next month or two, but in the the meantime it will be interesting to see if anyone is using the technique already. [SFGate via Slashgear via Verge]